What does it mean?
C1156 is a Chassis (ABS, traction control, steering) fault code. It indicates: Steering Angle Sensor CAN Communication .
Symptoms
- ABS, traction and stability control lamps on, often with a steering wheel warning symbol or text message
- Stability and traction control disabled, so no corrective braking in a slide
- Parking assist, lane keeping aid, adaptive lights or active steering functions stop working
- Scan tool cannot communicate with the steering angle sensor at all, or shows an angle stuck at one value
- Fault often appears at start-up and may clear briefly after a battery disconnect, then return
Likely causes
- Internal failure of the steering angle sensor mounted on the steering column
- Damaged clockspring or column connector, breaking the bus and supply lines that pass through it
- Broken, chafed or corroded CAN wiring between the column and the ABS / stability control module
- Sensor calibration lost or never carried out after a column, clockspring, steering rack or alignment job
- Low battery voltage or a bad ground causing the sensor to drop off the bus at key-on
- Another module dragging the bus down, so the steering angle message never arrives
- Failed ABS or stability control module that no longer receives or interprets the message
How to fix it
- Scan every module and note the U-codes; a communication fault stored in several modules points at the bus, not at the sensor
- Compare live steering angle with the real wheel position — driving straight ahead should read close to zero degrees
- Check the clockspring and the column connectors for broken wires, loose pins and damage from previous airbag or column work
- Measure the bus resistance across CAN high and low with the ignition off; roughly 60 ohms indicates the backbone terminations are intact
- Check power and ground at the sensor with the ignition on, and confirm the ground point behind the column is clean and tight
- Carry out the steering angle sensor calibration procedure; many cars need a wheel alignment check first for the zero point to be valid
- Replace the sensor or clockspring only after wiring, voltage and bus checks are clear, then recalibrate